Keyhole guard



June 5, 1923.

S. J. HOF F KEYHOLE GUARD l I l- INVENTOR JZeZHof'f A TTORNE Y Patented June 5, 192 3.

. sreoan ,JAHR HOFF, ba sman-K, N. Y.

Luz

KEYHOLE GUARD.

7 Application filed March 28, 1922. Serial No. 547,444.

To all whom it may) concern Be it known that I, SIGURD JALrR Horn, a citizen of the United States, residing at New'York, in the county of New York and State of New York, have invented certain new and useful Improvements in Keyhole Guards, of which the following is a specification.

This invention relates to looks and has particular reference to a means insertable in the keyhole of a lock, the main object being a lock which will safeguard the same from being picked or otherwise tampered with.

Another object is to design the device in such manneras to be proof against being broken off or jimmied out of the key hole, as is possible with the present day type of this class.

These and other objects will become apparent in the description belowq-in which characters of reference refer to the likenamed. parts in the. drawing.

Referring briefly to the drawing, Figure 1 is a sectional elevational View of a portion of a door showing my safety lock in the locked position in a keyhole.

Figure 2 illustrates a modified form of a safety lock.

Figure 3 is a front elevational view of the preferred form in the unlocked position.

Figure 4 is a side elevational view of the same.

Describing the drawing more in detail, the numeral 1 indicates a door panel having a conventional type of knob handle 2 and a door plate 3 secured thereto in the usual manner, on the inside of the door.

The modified form of safety lock illustrated in Figure 2 essentially comprises a pair of spaced parallel bars 4 joined to each by a half bend 5. The free ends of the bars 4 are bent into outwardly projecting portions 6. Y

The preferred form of lock shown in the remaining views is of an outline similar to the modified form, having a pair of spaced parallel bar members 7 joined at one end by a half bend 8. Each of said bars 7 slidably receive a tubularshell 9 having a longitudinal slot 10 which engages a fixed pin 11 located on each of the bars 7.

The free ends of shell 9 are provided with recesses 12 which receive a locking dog 13,

the latter being pivoted by the pin 14. These dogs are rotatable thru two quadrants, corresponding to the locked ;or released position. The dog secured to the upper bar, as

illustrated in Figure 3 is in the released position while the dog on the lower bar is shown locked.

Bars 7 are provided with detents 15 on the adjacent sides near member 8 and are adapted to register with cutout portions 16 of the tubular shells 9 when the latter'is in the positionshown in Figure 1. Obviously the yoke 17 of the padlock 18 will engage both the bars 7 and the shells 9 and retain the same in fixed relation to each other.

In use the safety lock is inserted in the keyhole of a lock, bend 8 entering first, and pushed inward-the locking dogs being ro'- tated to the position shown in Figure 1. Bar members 7 are then slid into the shells until the detents 15 registerwith 16 after which a padlock yoke 17 can be inserted through the detents thus securely locking the bar 7 within the shells. The dogs (13 contact with the ends of bars 7 when the latter is in locked position and prevent the rotation of the said dogs to the unlocked or re released position. i

As illustrated in Figure 1 the door panel 1 has a recess 19 formed therein on'the out-.

side surface of the door so that the dogs 13 j will not project beyond the door surface and permit the breaking ofi or snapping, of the same by a marauder.

In opening, the lock the padlock is re moved and the bars 7 are extended, by pulling outwardly, permitting the dogs to be urged into alignment'with the bars7. Further pull on the bend 8 will entirely withdraw the safety look from the "keyhole without the necessity of opening the door to do so. I claim l. A look of the class described comprising a pair of rigid parallel bars, slotted tubular members slidable on said bars, looking dogs pivoted at the ends of said tubular members, and adapted to. be locked in extended position and means for locking the said dogs in locked position.

2. The combination with a lock insertable in a key hole and a padlock, a pair of spaced parallel bars connected atone end, tubular members slidable on the said bars, and having recesses at the freeends, locking dogs pivotally mounted in said recesses, ends of said locking bars adapted to abut the ionthe detents of its corresponding bar when in locked position and a padlock engaging said detents and retaining the said dogs in locked position.

In witness whereof I affix my signature.

SIGURD JAHR HOFF. 

